Telephone desk set.



E. CRAFT. TELEPHONE DESK SET.

APPLICATION FILED MALI. I915- Patented Jan. 2,1917.

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E. B. CRAFT.

TELEPHONE DESK SET.

APPLICATION HLED MAR. 2. I915.

1,210,424. Patented Jan. 2, 1917.

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TELEPHONE DESK SET.

APPLICATION FILED MAR. 2. 1915.

Patented Jan. 2,1917.

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EDWARD B. CRAFT, OF HACKENSACK, NEW JERSEY, ASSIGNCR, BY MESNE ASSIGN-MENTS, TO WESTERN ELECTRIC COMPANY, INCORPORATED, A CORPORATION OF NEWYORK.

TELEPHONE DESK SET.

Patented Jan. 2, 1917.

Application filed March 2, 1915. Serial No. 11,488.

To all whom it may concern:

Be it known that I, EDWARD B. CRAFT a citizen of the United States,residing at l-lackensack, in the county of Bergen and State of NewJersey, have invented certain new and useful Improvements in TelephoneDesk Sets, of which'the following is a full, clear, concise,-and exactdescription.

This invention relates to improvements in the construction of telephonedesk sets, hav ing for its object the provision of. a single, compactand efficient construction in which the condenser and induction coil aremounted within the standard and base respectively of a desk set.

In accordance with this invention there is provided a hollow base havinga tubular standard rising therefrom, said standard carrying atransmitter element and switchhook upon its upper portion. A toroidalshaped induction coil is mounted within said base, and a cylindricallyshaped condenser is inclosed within said standard. Contacting andswitching means are provided for electrically connecting the varioustelephone elements in the same circuit. A clamping means is alsoprovided for rigidly holding the various elements comprising the deskset, in their respective order of assembly.

The nature and advantage of this invention will hereinafter more fullyappear.

This invention is illustrated in the accompanying drawings in which-Figure 1 is a front elevation, partly in section, of a telephone deskset embodying the features of this invention; Fig. 2 is a lan view ofthe mounting plate inclosed within the base; Fig. 3 is a detailedfragmentary view of the condenser and means for connecting the same inthe telephonic circuit; Fig. i is a side elevation of the condenser andspring assembly shown in Fig. 1; and Fig. 5-is a circuit diagram showingap paratus wired in accordance with this in vention.

Rising from a pedestal or hollow base 6 is a tubular standard 7 whichmay be removably mounted in said base by means of retaining ring 8having interior threads adapted to engage exterior threads formed uponthe lower extremity of said standard. The standard 7 has an upsetportion 9 formed near its base to limit the movement thereof into thebase 6. A transmitter element 10 and a switchhook ll-is carried. at

the upper portion of the standard 7. A mounting plate 12 comprising ametallic portion 13 and a non-metallic portion 1 1 is inclosed withinthe base 6. Secured to the non-metallic portion 14: are a plurality ofcontact members 15 which extend toward the center of the base 6. Aplurality of binding posts 16 are provided for connecting an extensioncord to the desk set. Secured by means of clamps 18, held in positionwith screws 19, is a toroidal shaped induction coil 17. A toroidalinduction coil is used, not only because its shape renders it convenientfor 'mounting inthis position, but mainly because its endless magneticcircuit practically eliminates a leakage field and the consequent energyloss in the metallic base 6. which would necessarily accompany the useof a solenoidalinduction coil. A cvlindrically shaped condenser 20 whichis supported by the mounting plate 12, extends upwardly into thestandard 7. The condenser 20 is provided with a plurality of ribs 21which terminate at one end in contact members 22 and at the other end incontact members 23. The ribs 21 are preferably positioned so as to beapproximately 120 apart thus avoiding the possibility of the contactscarried on their extremities from interfering with each other. Thecenter of the condenser 20 is made hollow so as to accommodate a rod 26,one end of which is threaded, while to the other end thereof there issecured an L-shaped bracket 27. By means of a nut 29, the bracket 27 maybe drawn down and rigidly held in position at the upper end of thecondenser 20. Any suitable means, such as a lug (not shown in thedrawing) punched from the short end of the bracket 27 may be employed topre vent the condenser 20 from rotating. A plurality of contact springs30 arranged in the form of a spring assembly and secured by means ofscrews 31, are attached in an upright position to the bracket 27. Theswitchhook 11 and a mounting piece 45 for the transmitter element 10, issecured in any suitable manner to the upper end of the bracket 27. Thecontact springs 30 are so positioned as to be in operative relation withthe switchhook 11 and make and break contact upon the actuation of saidswitchhook.

Contact members 23 are connected to the contacts 30 by means ofconductors 32. When the-condenser 20 and the elements attached theretoare inserted into the standard 7, contacts 22 mutually engage with thecontact springs 15 and this structure is held in place by means of a nut36 screwed upon the portion of the rod 26 which extends through anaperture in the mounting plate 12. A crow-foot 33,- mounted intermediatethe under surface of the base 6 and the retaining ring 8, furnishes ameans by which the mounting plate 12, through the medium of screwspassing through apertures 34, may be fastened within the base 6. Areceiver 37, when not in use, is supported by the switchhook 11. Theopening in the bottom of the base 6 may be closed by means of an annulardisk or plate member 38.

The circuit arrangement of the telephonic elements in accordance withthis invention may best be understood by reference to Fig. 5. The lowerpart of the figure shows the windings of the induction coil 17 properlyconnected to the contact members 15 and the binding posts 16. Conductors40 and 41 are the strands of a two-conductor cord which may be used toconnect the desk set with a desk set box, and conductors 42 and 43connect the receiver 37 to the contact member 15 and binding post 16,respectively. The connection through the condenser 20 is conventionallyrepresented and the contact members of said condenser and the inductioncoill7 are relatively represented as occupying the position which theyoccupy when in engagement with each other. A battery circuit for thetransmitter 10 may be traced by the'following path: conductor 40,binding post 16, primary winding of the induction coil 17 contactmembers 15, 22, rib 21, contact member 23, conductor 32, contact springs30, through the transmitter 10, conductor 32, contact member 23, rib'21, second set of contact members 22, 15, out over conductor 41. Thereceiver 37 is inductively connected to the circuit just described bythe following path: left hand binding post 16, conductor 43,-receiver37, conductor 42, contact members 15, 22, rib 21, contact member '23,conductor 32, through the transmitter 10, middle contact spring 30,conductor 32, contact member 23, condenser 20, second set of contactmembers 22, 15 secondary winding of the induction coil 17, back tobinding post 16.

From the above it will be seen that the general construction of a deskstand, which requires only a two-conductor cord, has been greatlysimplified, and a solid, compact structure obtained, in which all of theparts are easily accessible.

What is claimed is:

1. In a telephone desk set, a hollow base,

a mounting plate inclosed within said base, a toroidal shaped inductioncoil clamped to said plate, a tubular and removable standard rising fromsaid base, a transmitter element and switch-hook carried at the upperportion of said standard, a condenser 1nclosed within said standard,separable, and mutually engaging contact members carried respectively bysaid mounting plate and said condenser, clamping means for drawing andholding said plate, condenser and contact.

members together, and means for securing said base and standardtogether.

2. In a telephone desk set, a hollow base, a tubular standard risingfrom said base, a transmitter element and switchhook carried at theupper portion of said standard, a toroidal shaped induction coil mountedwithin said base, a condenser inclosed within said standard, means forconnecting said condenser and induction coil in the transmitter circuit,means for tightening and securing said elements in a given order withinsaid standard and base, and a clamping means for fastening said base andstandard together.

3. In a telephone desk set, a hollow base, a mounting plate inclosedwithin said base, a toroidal shaped induction coil secured to saidmounting plate, a tubular standard rising from said base, a transmitterelement carried at the upper portion of said standard, means ofconnection between said in cluction coil and said transmitter, and meansfor tightening and holding said elements together when assembled intheir proper order.

4. In a telephone desk set, a hollow base, a mounting plate inclosedwithin said base, a toroidal shaped induction coil clamped to saidplate, a tubular standard rising from said base, a transmitter elementand switchhook carried at the upper portion ofsaid standard, a condenserinclosed withinsaid standard, a plurality of metallic ribs passinglongitudinally through thebody of said con-- denser and terminating incontact members at each end thereof, said ribs serving as con-'-necting'links for connecting said condenser and induction coil in thetransmitter circuit, and means for tightening and holding said elementstogether when assembled in'their proper order.

5. In a telephonedesk set, a hollow base,

a mounting plate inclosed within said. base, a toroidal shaped inductioncoil clamped to said plate, a tubular standard rising from inglongitudinally through the body of said condenser and terminating incontact members at each end thereof, said ribs serving as connectinglinks for connecting said condenser and induction coil in thetransmitter circuit, means for preventing the rotation of saidcondenser, and means for tightening and holding. said elements togetherwhen assembled in their proper-order...

6. In a telephone desk set, a hollow base, a tubular standard risingfrom said base, a supporting plate comprising portions of conducting andnon-conducting material in closed within said base, a toroidal shapedinduction coil clamped to said supporting plate, a cylindrically shapedcondenser inclosed within said standard, a rod passing through saidcondenser and having its lower end threaded and adapted to fit into anaper ture formed in said mounting plate, an L shaped bracket secured tothe upper end of said rod, a contact spring assembly mounted upon saidbracket, a transmitter element and switchhook carried at the upper endof said bracket, said contact springs being controlled by saidswitchhook, a plurality of contact members depending from the lower endsof said condenser, contact springs secured to said mounting plate andadapted to mutually engage said contact members, means for tighteningand holding said condenser to said mounting plate, and means forfastening said standard and base together.

In witness whereof, I hereunto subscribe my name this 27th day ofFebruary A. D., 1915.

EDWARD B. CRAFT.

Witnesses:

E. EDLER, K. L. STAHL.

Copies of this patent may be obtained for five cents each, byaddressingthe Commissioner of Patents.

Washington, D. 0.

